My Rocket R58 for a while now has a louder noise.
I would like to make it more quiet.
I reassemble the chassis sides to make sure the pipes not touching the chassi, so that's not the issue here.
What do you think is the problem here, pump?
If it is the pump, which pump should I buy and are there any good instructions how to replace it?

I dont think that it has anything to do with it, but that portafilter looks to be way overtightened.

Mine usually stops about 11 o clock. If I really push it, I can get it to about 1 o clock. You are way past that.
I'd replace the gasket or try not to tighten it that much.

I assume you have the blind basket in there for this video.

Does it make the same loud noise when coffee is in the basket?

No that's not it... it just that I using other handle with smaller gasket.
Here is another one:

Any ideas guys?

Sorry man, I got nothing here. Diagnosing it over the internet is hard.

Not sure how comfortable you are with taking things apart, but I'd start looking inside with covers removed to see where the noise is coming from.

That should give you at least an idea of what part might be causing it.

Sounds like the pump mount has shifted and causing a resonance with the tubing / boiler / chassis

Check all the boiler / pump mounting hardware for proper tightening.

Try rolling a facecloth and insert between the tubing / frame. DO NOT put anything around the pump motor.